JAJSPF7D july   2003  – june 2023 SN74AHC245-Q1

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics
    6. 6.6  Switching Characteristics, VCC = 3.3 V ± 0.3 V
    7. 6.7  Switching Characteristics, VCC = 5 V ± 0.5 V
    8. 6.8  Noise Characteristics
    9. 6.9  Operating Characteristics
    10. 6.10 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Standard CMOS Inputs
      2. 8.3.2 Balanced CMOS 3-State Outputs
      3. 8.3.3 Wettable Flanks
      4. 8.3.4 Clamp Diode Structure
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Power Considerations
        2. 9.2.1.2 Input Considerations
        3. 9.2.1.3 Output Considerations
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 ドキュメントの更新通知を受け取る方法
    2. 10.2 サポート・リソース
    3. 10.3 Trademarks
    4. 10.4 静電気放電に関する注意事項
    5. 10.5 用語集
  12. 11Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.2.1.2 Input Considerations

Input signals must cross VIL(max) to be considered a logic LOW, and VIH(min) to be considered a logic HIGH. Do not exceed the maximum input voltage range found in the Absolute Maximum Ratings.

Unused inputs must be terminated to either VCC or ground. The unused inputs can be directly terminated if the input is completely unused, or they can be connected with a pull-up or pull-down resistor if the input will be used sometimes, but not always. A pull-up resistor is used for a default state of HIGH, and a pull-down resistor is used for a default state of LOW. The drive current of the controller, leakage current into the SN74AHC245-Q1 (as specified in the Electrical Characteristics), and the desired input transition rate limits the resistor size. A 10-kΩ resistor value is often used due to these factors.

The SN74AHC245-Q1 has CMOS inputs and thus requires fast input transitions to operate correctly, as defined in the Recommended Operating Conditions table. Slow input transitions can cause oscillations, additional power consumption, and reduction in device reliability.

Refer to the Feature Description section for additional information regarding the inputs for this device.